Well perforating apparatus



Sept. 24, 1963 Filed March 1, 1960 RADIOACTTVE SOURCE SLIDABLE COLLAR 44 SLIDABLE RADIOACTIVE AR SOURCE DETECTOR J. W. KENNEDAY ETAL WELL PERFORATING APPARATUS 2 Sheets-Sheet 1 ll FIG. 3.

. i aevansmu- MOTOR a] GEAR aox""'-- su RING 1 ASSEMBLY 5 LEADS To sum omscnou OF FIRE Fl (3. IA.

INVENTORS.

JOHN W. KENNEDAY,

ATTORNEY.

Sept. 24, 1963 J. w. KENNEDAY ETAL WELL PERFORATING APPARATUS Filed March 1, 1960 2 Sheets-Sheet 2 DETECTOR RECORDER FIG. 5. FIG. 6.

United States Patent 3,104,709 WELL PERFORATEYG APPARATUS John W. Keuneday, Corpus Christi, and James L. Rilte,

Houston, Tex, assignors, by mesne assignments, to

Jersey Production Research Company, Tulsa, ()khn, a

corporation of Delaware Filed Mar. 1, 1969, er. No. 12,047 2 Claims. ((31. 166-551) This invention concerns a method of orienting through tubing perforating guns to perforate the upper zones of conventionally cased multiple completions having two or more tubing strings and apparatus for performing the method.

Objects of the invention include a technique and apparatus for use therewith for properly orienting guns to perforate or reperforate the upper zones of conventionally cased multiple completions producing through two or more strings of tubing that avoid damage to the lower zone tubings and that eliminate the need for using offset orienting mandrels.

For the purpose of illustrating the invention in a simple, clear manner in the description of the invention to follow the use thereof is described with regard to only two tubing strings. It will be apparent from the description that the invention is adaptable for use with more than two tubing strings. Consequently, the invention is not to be considered limited to use with only two tubing strings. The V-shaped centralizers may be formed so as to straddle three or more tubing strings as to straddle one tubing string as will be described.

In brief, the apparatus of the invention includes a gun perforator assembly comprising perforating guns having a selected direction of fire; tubing or pipe string detecting means; V-shaped centralizer means arranged on said assembly; and means for rotating the assembly. The centralizer means are designed in a manner such that a lower zone tubing will fit within the V formed by the centralizer means and at the same time force the perforating gun against the side of the casing opposite the lower zone production tubing. The selected direction of fire of the gun perforator is opposite to or away from the direction of the V of the centralizer means. The top of the centralizer means is fixed to the assembly with the bottom free to move vertically to allow for lengthening due to compression of the centralizer means. The tubing detecting means may be any desired type; i.e., two radioactive sources, one of each located above and below the perforating guns, may be arranged on the assembly and two radioactive detectors may be run in the tubing the direction of which it is desired to detect; or detectors may be run in the tubing on the gun perforator and radioactive material may be placed in the tubing the direction of which it is desired to detect; or both a source of radiation and a detector of radiation may be arranged on the gun perforator and the induced radiation, caused by bombardment of the radioactive source on the tubing the direction of which it is desired to detect, may be detected by the detector.

In the method of the invention the assembly is run in the upper zone tubing until it is positioned adjacent the lower end thereof. The assembly is rotated with the rotating means through two or more revolutions to determine the maximum peak deflection on the detector recorder located at the earths surface. With these readings the perforating gun is oriented with the rotating device so that the gun charges will be facing away from the lower zone production tubing. The assembly is then lowered until a centralizer means is below the lower end of the upper zone tubing. The centralizer means then expands and forces the perforating gun against the easing. The assembly then is lowered to the desired perforating interval.

The above objects and other objects of the invention will be apparent from a description thereof taken in conjunction with the drawing wherein:

FIG. 1 is a vertical view of the gun perforator assembly of the invention;

FIG. 1A is a view taken on lines 1A1A of FIG. 1;

FIG. 2 is a cross-sectional view of two pipe strings, one of which contains the gun perforator assembly and the other of which contains two spaced-apart detectors of radiation;

FIG. 3 is a vertical partly sectional view of the rotating device portion of the gun perforator assembly;

FIG. 4 is a vertical view of the well bore containing two pipes or tubing strings and a schematic showing of the surface equipment for rotating the tool or assembly; for firing the guns; and for detecting the direction of the pipe it is desired to detect;

FIG. 5 is a vertical view of the Well bore adjacent the upper zone illustrating one step of the method of the invention;

FIG. 5A is a view taken on lines 5A5A of FIG. 5; and

FIG. 6 is a view similar to that shown in FIG. 5 except the entire tool or assembly is positioned out of the upper zone tubing string. a 1

Referring to the drawings in greater detail, in FIG. 1 a perforator tool '10 is suspended on a multi-electrical conductor cable 11. Tool 10 includes the following component parts: A device 12 for rotating the tool (the rotating device 12 is seen in greater detail in FIG. 3 and will be described relative to that figure); an upper directional radioactive source 13 arranged below rotating device 12, an upper positioner section 14; a gun section 15; a lower positioner section 16; and a lower directional radioactive source 17. e

Details of rotating device 12 will now be described. The device includes a housing 26 connected to a cable 11 in which is arranged a reversible motor 21 to which is connected a gear box 22 which, in turn, is connected to a rotatable shaft 23. -Hollow shaft 23 extends through the lower end of housing 20 and connects to housing 24 containing the upper radioactive source 13. Housing 20 has arranged therein bearings 24 which permit shaft 23 to rotate relative to housing 20 and sealing means such .as Q-n'ngs 25, which are adapted to prevent fluid from entering housing 20. Drag springs 26 are arranged on the exterior of housing 26 and function to prevent rotation of housing 2.0 and to centralize the housing in the tubing or pipe string. Shaft 23 may be provided with a slip ring assembly 27 for conducting electrical signals transmitted through a conductor 28 which is connected to cable 11 to conductors 29 which connect to gun elements 39 of the gun section 15. A conductor 31 connects cable 11 to motor 21.

'Radioactive source 13 contained in housing 24 and radioactive source 17 contained in a housing 32 are pnovided with shields configured so as to collimate the emanating radiation to confine the area of detection to a limited arc, as for example, an arc of 45 of the well bore. This limited arc of investigation is'more clearly seen in FIG. 1A.

As seen in FIG. 1A, the direction of fire 33 of gun elements 30 is away from the direction of the arc of de tection 34.

Any desired radioactive substance may be employed as the radioactive source. Examples of such materials are radon, radium bromide, radium chloride, uranium bromide, uranium tetrabromide, etc. These are naturally radioactive substances} however, known artificially radioactive substances also may be employed.

The shielding material for collimating the emanating radioactive beam may be formed of radiation absorbing or moderating materials, such as lead, tungsten, paraifin, boron, cadmium, etc., which material is capable of ab: sorbing or moderating the radiation being detected,

Positioning section 14 includes spaced-apart spring arms 40 and 41 connected at their upper ends to a collar 42 which is secured to a mandrel 43 which, in turn, connects to housing 24. The .lower ends of spring arms 40 and 41 are secured toa sliding collar 44 which is mounted for vertical movement on splined mandrel 43. As seen clearly in FIG. 1A, spring arms 40 and 41 form a V.

Lower positioning section 16 is similar to upper section 14 in that an upper collar 45 is secured to a mandrel 46 which, in turn, is connected to gun housing 15' in which are arranged gun elements 30. A lower collar 47 is slidably arranged on splined mandrel 46. Lower spring arms 48 and 49, which are shown in FIG. A, are connected at their upper ends to stationary collar 45 and at their lower ends to movable collar 47.

In FIG. 2, two spaced-apart pipe strings 5t and 51 are shown. In pipe string 50, upper and lower radiation detectors 52 and 53 interconnected by rod 54 are suspended on a multi-electrical-ly conductive cable 55. The detectors 52 and 53 are spaced so that the sources of radioactivity 13 and 17 are positioned at their respective levels. In pipe string 51, the gun perforator tool is arranged.

Detectors 52 and 53 may be any devices responsive to radiation produced by the radioactive material; for example, they may be Geiger-Mueller counters, ionization chambers, or proportional counters.

The surface equipment is shown in FIG. 4. Tubing 50 extends to the lower zone and tubing or pipe string 51 extends to the upper zone. Both tubings are shown arranged in a casing 60. Cable 55 connected to the detectors 52 and 53 arranged in pipe string 50 connects to detector recorders 61 and 62 which record the detected radiation of detectors 52 and 53, respectively.

Cable 11 connected to the gun perforator tool 10 connects to a control 6'3 for the reversible motor '21 and to a firing control 64 for the gun elements 30.

The operation of the invention is illustrated in FIGS. 5, 5A, and 6. As seen in FIG. 5, both tubing strings 50 and 51 extend through a dual bore packer 52, which is positioned above upper zone A. Tubing string 50 extends through a single bore lower casing packer 56 and adjacent a lower zone, not shown. In operation, tool 10 is lowered through pipe string 51 until. the lower end of tool 10 is adjacent the lower open end of pipe string 51, Then, detectors 52 and 53 are lowered on wire line or cable 55 in pipe'string 50 until they are positioned adjacent the perforator tool 10, as seen in FIG. 2.

Then readings are registered on the recorders 61 and 62 in order to determine whether the gun is properly oriented; i.e., that its direction of fire is away fnom pipe string 50 or stated another way that positioning spring arms will straddle pipe string 50 when the perforator tool is lowered through the lower open end of pipe string '51. If the gun elements are not properly oriented, the gun perforator tool 15 is rotated by operating motor 21 from rotation control 63. When the detector readings indicate that the gun elements are properly oriented, rotation is stopped and the perforator tool 15 is lowered out the lower end of tubing string 51 until only upper I positioning section 14 remains within the confines of tubing string 51. Then, another reading is taken on detector recorder 61 and 62 to check the position of the wardly once the spring arms are free from compression within tubing string 51. Also, as seen in particular in FIG. 6, once the centralizer armsare freed, they are designed to force the gun pertorator tool,15 against'the side of casing 60. Of course, the centralizers also are designed so that the lower zone tubing 50 is straddled by or fixed with the V fonmed by the arms.

Two detectors are used to illustrate the invention; however, it is possible to use but one detector and shift its position when readings are desired. Additionally, other type pipe detecting means may be employed. Forex ample, the source of radiation may be located in the lower zone tubing string and focused or collimatedde tectors used on the gun penforator tool; or both the source of radiation and the detector may be mounted or arranged on the gun perforator tool.

Having fully described the method, apparatus, objects,v

and operation of our invention, we claim:

1. Apparatus for perforating in a cased well bore having at least two eccentric, spaced-apart pipe strings arranged therein, one of said pipe strings being shorter than the other comprising a well tool adapted to be lowered in said one pipe string and including a perfonator having a selected radial direction of perforation, resilient expansible, retractable V-shaped centralizer means adapted to expand and straddle said other pipe string and force said well tool against the wall of said casing when said centralizer means is lowered through the lower end of said one pipe string, means for rotating said Well tool within said one pipe string, and a source of nadiation having a selected radial direction of bombardment; radiation detector means arranged in said other pipe string adapted to detect rays emitted by said radiation source; said direction of perforation and said direction or bombardment and said direction or expansion of said centralizer means being fixed relative to each other with the directionof perforation being in a direction other than in the direction of expansion ofsaid centralizer means.

2. Apparatus as recited in claim 1 wherein said centralizer means includes two spring arms extending spacedapart in a V-shiape in a radial direction, one end of each' arm being immovably secured -to said well tool and the other end of each arm being movably secured to said well tool.

References Cited in the file of this patent UNITED STATES PATENTS 2,785,754 True Mar. 19, 1957 2,938,584 Tausch et al. May '31, 196i)v Wat/Asmar 

1. APPARATUS FOR PERFORATING IN A CASED WELL BORE HAVING AT LEAST TWO ECCENTRIC, SPACED-APART PIPE STRINGS ARRANGED THEREIN, ONE OF SAID PIPE STRINGS BEING SHORTER THAN THE OTHER COMPRISING A WELL TOOL ADAPTED TO BE LOWERED IN SAID ONE PIPE STRING AND INCLUDING A PERFORATOR HAVING A SELECTED RADIAL DIRECTION OF PERFORATION, RESILIENT EXPANSIBLE, RETRACTABLE V-SHAPED CENTRALIZER MEANS ADAPTED TO EXPAND AND STRADDLE SAID OTHER PIPE STRING AND FORCE SAID WELL TOOL AGAINST THE WALL OF SAID CASING WHEN SAID CENTRALIZER MEANS IS LOWERED THROUGH THE LOWER END OF SAID ONE PIPE STRING, MEANS FOR ROTATING SAID WELL TOOL WITHIN SAID ONE PIPE STRING, AND A SOURCE OF RADIATION HAVING A SELECTED RADIAL DIRECTION OF BOMBARDMENT; RADIATION DETECTOR MEANS ARRANGED IN SAID OTHER PIPE STRING ADAPTED TO DETECT RAYS EMITTED BY SAID RADIATION SOURCE; SAID DIRECTION OF PERFORATION AND SAID DIRECTION OF BOMBARDMENT AND SAID DIRECTION OF EXPANSION OF SAID CENTRALIZER MEANS BEING FIXED RELATIVE TO EACH OTHER WITH THE DIRECTION OF PERFORATION BEING IN A DIRECTION OTHER THAN IN THE DIRECTION OF EXPANSION OF SAID CENTRALIZER MEANS. 